Importing files to iMac


I'm importing files from discs to an iMac for transfer to a Sony HAP. I've been using iTunes (MP3 at 192 kbytes), but it's been suggested I should use uncompressed AIFF. But iTune AIFF is limited to 48 kbytes. What's the tradeoff between compressed and lossless and bit-rate? Should I look for software other than iTunes for encoding disc files, and if so what?
Ag insider logo xs@2xdbphd
Abe knows his stuff. With SACD thru the Mac drive, is the HAP-Z writing a 24/96 hirez file?
I'm not sure what the HAP-Z1ES does.  I think it may upscale uncompressed encoding to DSD during playback, and attempt to address the loss from compressed encoding.
I should have written that I don't know if it writes a hirez file or converts it during playback.  I do know an SACD source sounds like an SACD.
If the HAP-Z rips SACDs as high rez that would be very big news. My understanding is that Sony has long held a strong position against the idea of ripping SACDs because of their interest in the sale of SACDs with their music biz. 
For many years the only way that anyone(and a small number) ripped SACD in high rez is by hacking a Sony Playstation of a certain vintage and doing some tweaking of the files. This is well documented online. Recently a similar routing to rip SACDs from Oppo players has gained popularity. You can find details on CA etc.
Contrary to @dbphd 's experience, IMHE it would be erroneous to conclude that ripped redbook layer from dual layer SACDs sound like SACD. Ripped SACD ISOs converted to 24/88 or 24/176 often sound like SACD, but occasionally get screwed up during the conversion process depending on the software used and settings (For me it's sometimes confusing!).
Many players show on their digital display during playback if the current song is SACD, HDCD etc. Does the HAP do that? If so at least it would be easy to confirm what the playback is looking at, 16/44, SACD or something else. Cheers,
Spencer